Ecommerce transactions, such as online sales and auctions, have now surpassed traditional consumer transactions in total revenue. Typically ecommerce transactions begin with a seller creating a listing, which includes an offer to sell or auction the item. The listing is created using one or more configuration parameters. For example, in the case of an online auction, a seller may be able to specify reserve price, starting bid, time of auction end, number of photos attached to listing, whether free shipping is offered, promotional placement, and other configuration parameters.